Newer window managers like Unity or early versions of Gnome 3 are terrible at running games smoothly. They either use some kind of windowed fullscreen mode, where they scale the window to span the whole desktop, or they have trouble managing demanding OpenGL applications and their own fancy window effects.

For best results, use the following:

– Gnome 2
– Gnome 3.4 or later
– (…more to come as we are testing various configurations)